How can I add very large numbers in C++?
A:
You could use a library like LiDIA for a 'big integer' class.
Geoffrey Chetwood
2008-12-04 05:22:55
A:
You can find a big decimal implementation at http://speleotrove.com/decimal/
tvanfosson
2008-12-04 05:24:50
A:
How big is "very large"? A signed long int can go up to 2,147,483,647 and an unsigned long int can go up to 4,294,967,295.
Patrick Harrington
2008-12-04 05:25:17
Not accurate sizeof(long) >= sizeof(int). So technically long only has to be as big as int (and on most systems nowadays is just 32). long long (A C extension not yet officially supported by C++) has a minimum of 64 bytes.
Martin York
2008-12-04 05:48:14
You mean 64 bits, not 64 bytes.
TonJ
2008-12-04 08:24:04
Accurate. sizeof(long) >= sizeof(int) is not the only requirement; the 32 bits range is another.
MSalters
2008-12-04 09:47:44
+3
A:
consider a "bignum" library like: http://gmplib.org/ or http://ttmath.slimaczek.pl/ttmath. take a look at a simple bignum class: http://www.circlemud.org/~jelson/560/
Ray Tayek
2008-12-04 05:26:39
+1
A:
Do a Google on "Bigint C++" This will provide you with a list of arbitrator precision integer arithmetic libraries.
Martin York
2008-12-04 05:52:04
A:
GMP has a GMPXX C++ wrapper which is kind of nice. GMP supports both integer and floating point numbers, and is LGPL'ed.
I've used it. It's ok, but watch out for creating lots of temporaries. (Potential efficiency hit.)
Mr.Ree
2008-12-04 08:26:36